[rfa] Contribute newlib Support for mep-elf (MeP

[Dave Brolley <brolley at redhat dot com>]

Hi,

The attached patch adds support for the mep-elf target to newlib. I 
would like approval to commit these changes and new files.

Thanks,
Dave

2007-11-05  Dave Brolley  <brolley@redhat.com>

	* libc/machine/configure: Regenerated to pick up mep-elf changes.
	
	* Contribute mep-elf from Red Hat
	2006-10-27  DJ Delorie  <dj@redhat.com>

	* libc/include/machine/setjmp.h: Add MeP support.

	2003-04-17  DJ Delorie  <dj@redhat.com>

	* configure.host (mep-*-*): Support "long long" type.

	2001-06-06  DJ Delorie  <dj@redhat.com>

	* libc/include/machine/ieeefp.h (mep): Support little endian too.

	2001-05-14  DJ Delorie  <dj@redhat.com>

	* configure.host: Add mep's machine_dir.
	* libc/include/setjmp.h: Add mep support.
	* libc/machine/mep: New, support mep's setjmp/longjmp.

	2001-05-04  DJ Delorie  <dj@redhat.com>

	* configure.host: Add mep.
	* libc/include/machine/ieeefp.h: Ditto.

Index: configure.host
===================================================================
RCS file: /cvs/src/src/newlib/configure.host,v
retrieving revision 1.96
diff -r1.96 configure.host
192a193,195
>   mep)
> 	machine_dir=mep
> 	;;
430a434,437
>   mep-*-*)
> 	default_newlib_io_long_long="yes"
> 	newlib_cflags="${newlib_cflags} -DMISSING_SYSCALL_NAMES"
> 	;;
Index: libc/include/machine/ieeefp.h
===================================================================
RCS file: /cvs/src/src/newlib/libc/include/machine/ieeefp.h,v
retrieving revision 1.32
diff -r1.32 ieeefp.h
312a313,320
> #ifdef __mep__
> #ifdef __LITTLE_ENDIAN__
> #define __IEEE_LITTLE_ENDIAN
> #else
> #define __IEEE_BIG_ENDIAN
> #endif
> #endif
> 
Index: libc/include/machine/setjmp.h
===================================================================
RCS file: /cvs/src/src/newlib/libc/include/machine/setjmp.h,v
retrieving revision 1.33
diff -r1.33 setjmp.h
225a226,230
> #ifdef __mep__
> /* 16 GPRs, pc, hi, lo */
> #define _JBLEN 19
> #endif
> 
Index: libc/machine/configure.in
===================================================================
RCS file: /cvs/src/src/newlib/libc/machine/configure.in,v
retrieving revision 1.8
diff -r1.8 configure.in
44a45
> 	mep ) AC_CONFIG_SUBDIRS(mep) ;;

dnl This is the newlib/libc/machine/mep configure.in file.
dnl Process this file with autoconf to produce a configure script.

AC_PREREQ(2.59)
AC_INIT([newlib],[NEWLIB_VERSION])
AC_CONFIG_SRCDIR([Makefile.am])

dnl Can't be done in NEWLIB_CONFIGURE because that confuses automake. 
AC_CONFIG_AUX_DIR(../../../..)

NEWLIB_CONFIGURE(../../..)

AC_CONFIG_FILES([Makefile])
AC_OUTPUT

## Process this file with automake to generate Makefile.in

AUTOMAKE_OPTIONS = cygnus

INCLUDES = $(NEWLIB_CFLAGS) $(CROSS_CFLAGS) $(TARGET_CFLAGS)

AM_CCASFLAGS = $(INCLUDES)

noinst_LIBRARIES = lib.a

lib_a_SOURCES = setjmp.S

ACLOCAL_AMFLAGS = -I ../../..
CONFIG_STATUS_DEPENDENCIES = $(newlib_basedir)/configure.host

#
#  Setjmp/longjmp for MeP
#
#  19 32-bit words in the jmpbuf:
#    $0
#    $1
#    ...
#    $15
#    $pc
#    $hi
#    $lo
#
#  Note that $0 is saved but not restored.  It can't be restored
#  as it's the return value of setjmp, but we save it in case
#  some application wants to see it in the jmp_buf.  Ideally,
#  we should not need to save anything that is call-clobbered,
#  but you never know what the user is going to tell gcc with -f
#  options.

	.noregerr
	.text

	.globl	setjmp
	.type	setjmp,@function

setjmp:

	# $1 is the address of the buffer.  We return 0 in $0.

	sw	$0, ($1)
	sw	$1, 4($1)
	sw	$2, 8($1)
	sw	$3, 12($1)
	sw	$4, 16($1)
	sw	$5, 20($1)
	sw	$6, 24($1)
	sw	$7, 28($1)
	sw	$8, 32($1)
	sw	$9, 36($1)
	sw	$10, 40($1)
	sw	$11, 44($1)
	sw	$12, 48($1)
	sw	$13, 52($1)
	sw	$14, 56($1)
	sw	$15, 60($1)

	ldc	$0, $lp
	sw	$0, 64($1)
	ldc	$0, $opt
	sra	$0, 24
	and3	$0, $0, 3
	beqz	$0, sj_skip_hilo
	ldc	$0, $hi
	sw	$0, 68($1)
	ldc	$0, $lo
	sw	$0, 72($1)
sj_skip_hilo:

	mov	$0, 0
	ret

	.globl	longjmp
	.type	longjmp,@function

longjmp:

	# $1 is the address of the buffer.  $2 is the value setjmp
	# returns.  We do not faithfully restore $0 or $lp, because
	# the act of calling setjmp clobbered those anyway.

	bnez	$2, rv_not_zero
	mov	$2, 1
rv_not_zero:

	# We restore $sp first so we can save the return value there,
	# otherwise we'd need to have another unrestored register.
	lw	$15, 60($1)
	add3	$sp, $sp, -4
	sw	$2, ($sp)

	# Now restore the general registers.
	lw	$2, 8($1)
	lw	$3, 12($1)
	lw	$4, 16($1)
	lw	$5, 20($1)
	lw	$6, 24($1)
	lw	$7, 28($1)
	lw	$8, 32($1)
	lw	$9, 36($1)
	lw	$10, 40($1)
	lw	$11, 44($1)
	lw	$12, 48($1)
	lw	$13, 52($1)
	lw	$14, 56($1)

	# We restore $pc's value to $lp so that we can just ret later.
	lw	$0, 64($1)
	stc	$0, $lp
	ldc	$0, $opt
	sra	$0, 24
	and3	$0, $0, 3
	beqz	$0, lj_skip_hilo
	lw	$0, 68($1)
	stc	$0, $hi
	lw	$0, 72($1)
	stc	$0, $lo
lj_skip_hilo:

	# Restore $1
	lw	$1, 8($1)

	# Get the return value off the stack, and restore the stack.
	lw	$0, ($sp)
	add3	$sp, $sp, 4

	ret